Bioactive Glass-Ceramic Scaffolds from Novel ‘Inorganic Gel Casting’ and Sinter-Crystallization
Highly porous wollastonite-diopside glass-ceramics have been successfully obtained by a new gel-casting technique. The gelation of an aqueous slurry of glass powders was not achieved according to the polymerization of an organic monomer, but as the result of alkali activation. The alkali activation...
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MDPI AG
2017-02-01
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| Series: | Materials |
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| Online Access: | http://www.mdpi.com/1996-1944/10/2/171 |
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| author | Hamada Elsayed Acacio Rincón Romero Letizia Ferroni Chiara Gardin Barbara Zavan Enrico Bernardo |
| author_facet | Hamada Elsayed Acacio Rincón Romero Letizia Ferroni Chiara Gardin Barbara Zavan Enrico Bernardo |
| author_sort | Hamada Elsayed |
| collection | DOAJ |
| description | Highly porous wollastonite-diopside glass-ceramics have been successfully obtained by a new gel-casting technique. The gelation of an aqueous slurry of glass powders was not achieved according to the polymerization of an organic monomer, but as the result of alkali activation. The alkali activation of a Ca-Mg silicate glass (with a composition close to 50 mol % wollastonite—50 mol % diopside, with minor amounts of Na2O and P2O5) allowed for the obtainment of well-dispersed concentrated suspensions, undergoing progressive hardening by curing at low temperature (40 °C), owing to the formation of a C–S–H (calcium silicate hydrate) gel. An extensive direct foaming was achieved by vigorous mechanical stirring of partially gelified suspensions, comprising also a surfactant. The open-celled structure resulting from mechanical foaming could be ‘frozen’ by the subsequent sintering treatment, at 900–1000 °C, causing substantial crystallization. A total porosity exceeding 80%, comprising both well-interconnected macro-pores and micro-pores on cell walls, was accompanied by an excellent compressive strength, even above 5 MPa. |
| first_indexed | 2024-04-13T13:30:29Z |
| format | Article |
| id | doaj.art-760067473acb420ebe13658ca78c76a6 |
| institution | Directory Open Access Journal |
| issn | 1996-1944 |
| language | English |
| last_indexed | 2024-04-13T13:30:29Z |
| publishDate | 2017-02-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Materials |
| spelling | doaj.art-760067473acb420ebe13658ca78c76a62022-12-22T02:44:59ZengMDPI AGMaterials1996-19442017-02-0110217110.3390/ma10020171ma10020171Bioactive Glass-Ceramic Scaffolds from Novel ‘Inorganic Gel Casting’ and Sinter-CrystallizationHamada Elsayed0Acacio Rincón Romero1Letizia Ferroni2Chiara Gardin3Barbara Zavan4Enrico Bernardo5Department of Industrial Engineering, University of Padova, Via Marzolo 9, 35131 Padova, ItalyDepartment of Industrial Engineering, University of Padova, Via Marzolo 9, 35131 Padova, ItalyDepartment of Biomedical Sciences, Universiy of Padova, via Ugo Bassi 58/B, 35131 Padova, ItalyDepartment of Biomedical Sciences, Universiy of Padova, via Ugo Bassi 58/B, 35131 Padova, ItalyDepartment of Biomedical Sciences, Universiy of Padova, via Ugo Bassi 58/B, 35131 Padova, ItalyDepartment of Industrial Engineering, University of Padova, Via Marzolo 9, 35131 Padova, ItalyHighly porous wollastonite-diopside glass-ceramics have been successfully obtained by a new gel-casting technique. The gelation of an aqueous slurry of glass powders was not achieved according to the polymerization of an organic monomer, but as the result of alkali activation. The alkali activation of a Ca-Mg silicate glass (with a composition close to 50 mol % wollastonite—50 mol % diopside, with minor amounts of Na2O and P2O5) allowed for the obtainment of well-dispersed concentrated suspensions, undergoing progressive hardening by curing at low temperature (40 °C), owing to the formation of a C–S–H (calcium silicate hydrate) gel. An extensive direct foaming was achieved by vigorous mechanical stirring of partially gelified suspensions, comprising also a surfactant. The open-celled structure resulting from mechanical foaming could be ‘frozen’ by the subsequent sintering treatment, at 900–1000 °C, causing substantial crystallization. A total porosity exceeding 80%, comprising both well-interconnected macro-pores and micro-pores on cell walls, was accompanied by an excellent compressive strength, even above 5 MPa.http://www.mdpi.com/1996-1944/10/2/171alkali activationgel castingbioactivitywollastonitediopsideglass-ceramics |
| spellingShingle | Hamada Elsayed Acacio Rincón Romero Letizia Ferroni Chiara Gardin Barbara Zavan Enrico Bernardo Bioactive Glass-Ceramic Scaffolds from Novel ‘Inorganic Gel Casting’ and Sinter-Crystallization Materials alkali activation gel casting bioactivity wollastonite diopside glass-ceramics |
| title | Bioactive Glass-Ceramic Scaffolds from Novel ‘Inorganic Gel Casting’ and Sinter-Crystallization |
| title_full | Bioactive Glass-Ceramic Scaffolds from Novel ‘Inorganic Gel Casting’ and Sinter-Crystallization |
| title_fullStr | Bioactive Glass-Ceramic Scaffolds from Novel ‘Inorganic Gel Casting’ and Sinter-Crystallization |
| title_full_unstemmed | Bioactive Glass-Ceramic Scaffolds from Novel ‘Inorganic Gel Casting’ and Sinter-Crystallization |
| title_short | Bioactive Glass-Ceramic Scaffolds from Novel ‘Inorganic Gel Casting’ and Sinter-Crystallization |
| title_sort | bioactive glass ceramic scaffolds from novel inorganic gel casting and sinter crystallization |
| topic | alkali activation gel casting bioactivity wollastonite diopside glass-ceramics |
| url | http://www.mdpi.com/1996-1944/10/2/171 |
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